The present invention relates to a high- and medium-voltage gas-insulated switchgear device, i.e. for voltages greater than 1000 Volt The device according to the present invention comprises a very simple and effective system for realizing both the interruption and disconnection operations.
It is known from the prior art that electrical operations, both for interruption and for disconnection, in high- and medium-voltage gas-insulated switchgear devices are performed by moving a moving contact. This is allowed by an actuation system for performing the electrical operation.
For interruption and disconnection operations, the actuation devices most frequently used in the conventional gas-insulated systems are of the mechanical or hydraulic type.
Mechanical actuation devices generally require complicated kinematic systems for transmitting the movement to the moving contact and complicated adjustment processes, because the rule of motion of the moving contact is determined exclusively by the mechanical characteristics of the involved structural elements and cannot be changed by the user, but is set at the design stage.
Because of the presence of complicated kinematic chains, the response time is relatively long. In order to achieve shorter response times it is necessary to provide much more energy than required to move the single movable mechanical element.
Moreover, said rule of motion can vary over time due to the wear of the single components, leading to a degradation in performance and therefore to the need to perform a large number of maintenance interventions in order to maintain the nominal behavior of the actuation system.
Hydraulic-type actuation devices partially solve these problems but have several drawbacks due to the presence of fluids and most of all to the sensitivity of said fluids to temperature variations.
Some conventional gas-insulated devices use, for the electrical operations, actuation and control systems which comprise electric motors which are manually actuated by an operator.
Even these actuation and control systems, despite fulfilling their task, are characterized, like the previously described ones, by lack of control over the rule of motion of the mechanical element that they move.
Lack of control over the rule of motion, both during the interruption operation and during the disconnection operation, requires the presence of stroke limiting devices in order to limit the movement of the moving contact and the presence of shock absorbers or dampers in order to dissipate the residual kinetic energy at the end of the operation.
Because of lack of control over the rule of motion, the positioning of the moving contact itself is inaccurate and can lead to early wear of the mechanical parts affected by the electrical operation.
Lack of control over the rule of motion during the interruption and disconnection operations makes it difficult to coordinate them correctly, this requires several interventions, with a considerable increase in the time required to complete the operation.
Further drawbacks are also caused by the dynamic behavior of the actuation means, especially during interruption operations.
The aim of the present invention is to provide a high- and medium-voltage gas-insulated switchgear device, in which the actuation of the moving contact of the interruption and/or disconnection elements occurs according to a preset rule of motion.
Within the scope of this aim, an object of the present invention is to provide a high- and medium-voltage gas-insulated switchgear device which has a reduced mechanical complexity.
Another object of the present invention is to provide a high- and medium-voltage gas-insulated switchgear device in which the interruption and disconnection operations are executed in shorter times in relation to the known devices.
Another object of the present invention is to provide a high- and medium-voltage gas-insulated switchgear device in which repeatability of the interruption and/or disconnection operation is ensured, optionally compensating for variations caused by aging and wear.
A further object of the present invention is to provide a high- and medium-voltage gas-insulated switchgear device which is compact and has reduced dimensions.
A further object of the present invention is to provide a high- and medium-voltage gas-insulated switchgear device which is highly reliable, relatively easy to manufacture and at competitive costs.
This aim, these objects and others which will become better apparent hereinafter are achieved by a high- and medium-voltage gas-insulated switchgear device, characterized in that it comprises a casing which contains:
at least an interruption unit having at least one fixed contact and one moving contact which can couple each other, and first actuation means which are operatively connected to the moving contact;
at least a disconnection unit electrically connected to the interruption unit, said disconnection unit having at least one fixed contact and one moving contact which can couple each other, and second actuation means which are operatively connected to the moving contact;
and in that at least one of said actuation means comprises a motor with position control.
The use of a motor with position control allows, among other things, to precisely apply a preset rule of motion during electrical operations.
Control of the rule of motion of the moving contact allows to ensure the accuracy and repeatability of the operation and its execution in a reduced time.
The use of a motor with position control allows a simplification of the overall mechanical structure of the device according to the invention, reducing the dimensions and increasing the reliability of the system.
The device according to the present invention can be of the segregated-phase or joined-phase type and of the single-pole or three-pole actuation type.
Further characteristics and advantages of the invention will become apparent from the description of preferred but not exclusive embodiments of a high- and medium-voltage gas-insulated switchgear device according to the invention, illustrated only by way of non-limitative example in the accompanying drawings, wherein: